<template>
  <div class="counter">
    <button @click="decrease">减少</button>
    <input type="text" v-model="value">
    <button @click="increase">增加</button>
  </div>
</template>

<script>
export default {
  name: 'HelloWorld',
  data(){
    return { value: 999 }
  },
  methods: {
    decrease(){
      this.value--;
    },
    increase(){
      this.value++;
    }
  }
}
</script>

<style>
.counter{
  border: 1px solid blue;
}
</style>
